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I agree. Evidence is hidden in plain sight:
O'Shea Jackson (born June 15, 1969), better known by his stage name Ice Cube, is an American rapper, actor, screenwriter, film director, and producer.
He began his career as a member of C.I.A and later joined the rap group N.W.A

And he's already committed crimes against humanity! Like "Are We There Yet?",and just when you thought it was bad, he made a sequel! This man must be stopped, perhaps by putting him someplace really cold, in fact I hear there's a continent if you go really far south that's just covered in ice...

I hear they have top doctors working on an easy plan to use yellow fever to infect humans via wild wrens. Leaving us nothing but doggs and bones with little to eat but M&Ms wishing we were an exibit on deathrow in the aftermath.

No, seriously. I think I remember reading about this earlier this year in Scientific American or something... only it was on a big lake in Russia [thelivingmoon.com] and they worked during the winter when everything is frozen. Kind of cool, bleeding edge stuff.

I gather that the one in the Antarctic will be bigger, and give a view in a different direction than the Russian one.

But that's what it sees - the sensors point at the Earth and the filter software discards muon events that track from the sky, keeping events that come from underneath since muons coming from the Northern Hemisphere decay long before they can reach the detector. Neutrinos survive passing through thousands of miles of rock, so if it comes from the middle of the Earth, it's a neutrino. If it comes from the sky, it could be a neutrino, but chances are, it's a muon.

It can infer the direction a neutrino came from, so (given enough time) it can make "images". In fact, they've seen the moon [arxiv.org] already, as a deficit of neutrinos coming from the moon's direction. It is a telescope, just one that doesn't "see" photons and that you don't have to point at a target to see it.

It's omni-directional. The detectors are placed in a way that it can detect the arrival of neutrinos coming from any direction (including, and specially, from below the horizon). This way, we can get a "whole sky" image at once, without moving anything in the experiment.

It's ability to trace the sky using a carrier that was never explored in this way (except to "see" what happens in the sun, and during a nearby supernova).

Using optical telescopes, we can get an image of how the universe looks in visible photons. In an x-ray telescope, we get an image of the universe in x-ray photons. In a cosmic ray telescope, we get an image in charged particles. IceCube (plus its northern sister, KM3Net) should be able to get an image of the universe in neutrinos with energies over 1 TeV

Yes, that is why it detects "specially" what comes from below the horizon (or from the northern sky). However, they have some sensitivity to downgoing neutrinos (coming from above the horizon, or from the southern sky), if they arrive with an energy so high that the atmospheric muon background at those energies would be negligible. Or, being more technically correct, they use an array of cosmic ray detectors in the surface [udel.edu] to identify if an event whose energy is above a certain threshold and coming from "ab

Your eyes are a "telescope". We usually reserve the word for instruments that let us examine astrophysical objects in a way that we can't do with our naked eyes, but an optical telescope works in exactly the same way as your eyes. Just change the retina for a CCD.

Yes, I read through the whole article looking for an explanation of why it is referred to as a telescope. Then I was scanning through these comments for someone to explain to me how this is a telescope, figuring somewhere there had to be a couple people duking out the actual meaning of telescope, or at least the difference between a telescope and a detector...why not a microscope...

From Wikipedia

A telescope is an instrument designed for the observation of remote objects by the collection of electromag

I assumed they were using the term telescope to satisfy public curiosity, but it only served to confuse me further. It isn't actually looking at the sky though, nor can it see it from what I read, it simply sees reactions of the earth to neutrinos, the scientists then use that data to extrapolate what is happening in the universe. Much the same way that I can make observations about the weather by looking at the electronic thermometer in my bathroom, that doesn't make it Doppler radar..

Agreed, at least provisionally. A telescope is an instrument which "sees" objects at a "distance". Whether the mechanism is optical or otherwise is not the point, it's how effectively the device can give us information about specific distant objects.

This array is more like a scintillation counter. It measures local phenomena. Perhaps, opportunistically, it could be used to infer something about distant objects, but in that sense it's still no more a telescope than a light bulb is a power meter.

Why? It captures information from a flux of particles (not photons, but neutrinos in this case) emitted by astrophysical objects. It allows us to study properties of those objects (and of the detected particles as well). It doesn't have a resolution high enough to give us an "image" of most of those objects, but Hubble can't image most single stars too. IceCube won't give you a pretty picture for APOD, but it will do everything else we can do with an optical telescope, or a charged particle telescope such a

Why? It captures information from a flux of particles (not photons, but neutrinos in this case) emitted by astrophysical objects.

Because when speaking to a broad audience it behooves scientists to avoid terminology that they know will be confusing and misleading to laypeople. Anything else is an abrogation of their responsibility to communicate science clearly and unambiguously to the public.

Besides, no one in these fields ever calls anything like this an (unqualified) telescope. So the purpose of doing so for a general audience seems to me to be solely to mislead and confuse, and I'm not at all clear why anyone would want to do th

Besides, no one in these fields ever calls anything like this an (unqualified) telescope.

Yeah, but they do say things like radio telescope or x-ray telescope, and those are very different from what most laypeople think of as a telescope. I certainly think that omitting the word "neutrino" was a big mistake, but does it go beyond that? The question is, can it be called a type of telescope?

Curiously, the link you provide to Auger describes it as a "cosmic ray observatory", almost as if the people who create

Anything else is an abrogation of their responsibility to communicate science clearly and unambiguously to the public.

The only time theres a 'responsibility' to communicate science 'clearly and unambiguously to the public' is when a government administration is trying to justify public spending on science to the electorate.

And thats not a responsibility of the scientists.

The scientist has a responsibility to communicate science clearly and unambiguously to OTHER SCIENTISTS.

actually it is looking at events created locally by neutrinos from my understanding, it isn't actually recording ANY remote events. Of course by this logic you could consider any telescope just to be recording particles that hit the telescope. But I maintain this is more of a microscope than a telescope.

Theoretically, you could toss a raw CCD on the floor and take a 180 degree picture. You'd need some fancy software that probably doesn't exist at the moment. But would it be a camera? Would it be a telescope? I assert neither, and that this observatory is neither as well.

I wondered about this, too. I don't think that telescope is incorrect, exactly, but it would be better perhaps to call it an Observatory.

The key feature of a telescope as I interpret the word is amplification of visual phenomena. It makes tiny things seem big. Perhaps the nitpickers would say that the main feature of a telescope is that it can resolve finer and finer details - I'd say that's the same thing. An ancillary of this is that it tends to gather a large amount of otherwise feeble light from some small field-of-view so that, when that field of view is zoomed in to occupy the whole of a sensor (a camera, the eye, etc.) there is still something there to see.

This neutrino detector doesn't have any sort of magnification in that sense. It doesn't even work in the electromagnetic spectrum! It's purpose isn't to zoom in on a phenomenon, but to detect it and tell us where it came from. It doesn't zoom in. By that token I would say that it is an observatory, not a telescope. It does, however, have light amplification through the use of photomultipliers. And, by virtue of its size, can be thought of as having better resolving power and sensitivity than its predecessors. By measuring neutron flux intensity as a function of angular position, it should be able to produce a sky map much that those from more conventional (optical, radio, IR) telescopes. Does this make it a telescope? I don't know.

For comparison, the Compton Gamma Ray Observatory [wikipedia.org] faced a similar challenge: it didn't have an aperture or light gathering and focusing mirrors common to "telescopes" of other wavelengths. It is not possible to do that with any materials we're familiar with - gamma rays are absorbed or pass right through; there can be no reflectance or refraction. GRO was, much like this neutrino experiment, a target that waited for gamma rays to pass through. Once they did the instruments would figure out their energy and where in the sky their originated from. Notice that they called it an "observatory", not a "telescope."

I think amplification is the wrong criteria to define a telescope, a better criteria would be "convergence" or "focusing" of whatever spectrum we are looking at. That is the only common theme I can see in a Telescope, they all converge large amount of spectrum to a focal point. This may not be in a physical sense and may be done inside of a computer via munging of captured data from various physical detectors.

In that respect, I still come to the same conclusion, that this is not a telescope.

This may not be in a physical sense and may be done inside of a computer via munging of captured data from various physical detectors.

In that respect, I still come to the same conclusion, that this is not a telescope.

Um, if you accept that a telescope need not focus by using physical reflection but by combining data from multiple detectors distributed over an area, then this would most definitely be a telescope in that respect.

If we must for some reason draw a distinction between traditional telescopes and

> That is the only common theme I can see in a Telescope, they all converge> large amount of spectrum to a focal point. This may not be in a physical> sense and may be done inside of a computer via munging of captured data from> various physical detectors.

The key feature of a telescope as I interpret the word is amplification of visual phenomena. It makes tiny things seem big.

This neutrino detector doesn't have any sort of magnification in that sense. It doesn't even work in the electromagnetic spectrum! It's purpose isn't to zoom in on a phenomenon, but to detect it and tell us where it came from. It doesn't zoom in.

Sure it does. It allows you to take a source of infrequent interactions and amplifies them by increasing the size of the detector. This is wh

I think it's correct to call IceCube an observatory, but not a telescope. All telescopes are observatories, but the inverse isn't true. Observatory is a broad term (my house can be an observatory), but telescope refers to a specific kind of instrument (I definitely do not live in a telescope).

That was the point of my last paragraph... Observatories are facilities that contain astronomical instruments. But you don't call the instrument itself an observatory whether that instrument is a telescope or not.

There should be no dispute whatsoever that IceCube is an observatory. But I think it is fair to call it a neutrino telescope as well.

For a telescope that detects photons (the normal meaning of telescope) area is key, because pretty much all the photons (or at least a large fraction) that are "collected" end up triggering the sensor (CCD, film, whatever) even when it is thin. For neutrinos, they hardly interact with matter at all, and the larger volume is needed. The neutrino detection experiment in Japan (I can't recall its name at the moment) is basically a huge tank of water underground surrounded by detectors that detect flashes of li

As someone working in this exact field I would say no. Where are you going to put it ?
The idea of burying it deep in a refracting medium is to eliminate cosmic rays as background noise, and allowing the neutrino to produce a muon which will do a Cherenkov light in the detector.
You need a deep refracting medium for this, beside we use the whole earth as a detector because of the low cross-section the neutrino have. So with a smaller stellar body(the moon) you will have less neutrinos interacting, and this less data to work with.

Actually yes, the near vacuum condition will help a lot on the angular resolution. But you will run into a lot of problems: The near vacuum conditions will mean that for the muon to create a Cherenkov light cone it would have to be hyper-relativistic. Since the muons energy is about 33% of that of the neutrino, most Energy fluxs are decreasing with energy(negative power laws), and with a lower stellar mass(of the moon). You will detect far less events in general, specially in the lower energy region.
If you can place your detector in a refracting medium(let's say water), with a reasonably sized telescope (1km3), I will let you do the calculation on how much water we will need, with all the electronics problem that are associated with it.

Ice Cube operates by observing visible Cerenkov radiation from electrons and muons created when high-energy neutrinos hit an atom in the ice, as they traverse the ice. Of course, ice being transparent to visible light is important here, and lunar regolith is opaque to visible light.

However it has been proposed to look for radio waves being emitted in a similar manner. Cerenkov radiation [wikipedia.org] is caused by moving faster than the speed of light in the medium -- it's the "blue glow" if you look at the picture on that wikipedia link, and emits a broad spectrum of radiation, down into radio frequencies. Depending on the composition of the regolith, it may be transparent to radio waves. This can be done from the Earth by pointing your antenna at the moon, or from satellite(s) in orbit around the moon. You might be interested in the Goldstone [ucla.edu] project. So, at least with proposals I've heard about, getting people on the moon to make big holes is not an important component, but the surface of the moon may still be useful for similar experiments. You never know though, maybe tomorrow someone will post a new idea!

Would there, however, be any benefit to having such a project set up under lunar regolith/base rock if we could ever get back to the moon?

Yes.

The reason why: there are virtually no high-energy muons in lunar cosmic rays, and high-energy muons, one way or another, are the major cosmic-ray background in these experiments.

The reason why there are virtually no high-energy muons in lunar cosmic rays is due to their primary mechanism of production: on Earth, cosmic-ray protons smack into atoms at the top of the atmosphere, producing high energy pions, which decay into muons etc... and because of the low density of the atmosphere, the decay time is much less than the stopping time, so the muons have most of the orignal energy of the primary cosmic ray available to them.

On the Moon, which notably lacks an atmosphere, the primay cosmic rays smack into the lunar regolith and therefore the pions are created in a very dense medium, and lose most or all of their energy before decaying. The muons thus created are relatively low energy and stop within a few meters--as opposed to terrestrial cosmic ray muons which are still seen in experiments like the Sudbury Neutrino Observatory, 2 kilometres underground.

As such, a relatively small, relatively shallow detector on the Moon could produce comparable performance to the best terrestrial detectors, at only a few orders of magnitude higher cost.

It may be worth mentioning that no one working in the field ever calls a neutrino detector a "telescope", as in English that word when used without qualification virtually always means "optical telescope", so the usage in this article is misleading and confusing, to the point where if were done deliberately I would consider the person doing it to be either stupid or dishonest. I guess maybe the person who wrote the article or provided the information for it has English as a second language.

It may be worth mentioning that no one working in the field ever calls a neutrino detector a "telescope", as in English that word when used without qualification virtually always means "optical telescope", so the usage in this article is misleading and confusing, to the point where if were done deliberately I would consider the person doing it to be either stupid or dishonest. I guess maybe the person who wrote the article or provided the information for it has English as a second language.

Sure, unqualified it implies optical, but on the other hand we have radio telescopes, infrared telescopes, x-ray telescopes, and gamma-ray telescopes. Why not the IceCube neutrino telescope? Surely, though, the lack of the word "neutrino" in the title and the summary was a gross omission.

I agree that the background reduction due to lack of atmosphere is very convenient, but as zero.kalvin points out, you still need a 'refracting medium', that is, a really large volume of transparent material such as water or ice (in which you can catch the Cherenkov light whenever a neutrino is kind enough to interact and produce fast charged particles). The large volume is not needed to suppress background, but to beat the very small cross section; in order to detect neutrinos you need them to interact wit

The large volume is not needed to suppress background, but to beat the very small cross section; in order to detect neutrinos you need them to interact with your detector, and the only way to achieve that is to make it as big as possible.

Yes, and then again no. I have designed and built (reactor) neutrino detectors that have a volume of less than a cubic metre (and some very impressive background-suppression tricks) and have detected reactor neutrinos (~10 m from the core).

Background is not simply separable from rate. In particular, background tends to ramp up as energy goes down, so even though there are many more low-energy neutrinos in most interesting cases we typically are cut off at a few MeV because of backgrounds. The Moon offers

The Hubble doesn't count because it's nowhere near the largest. It doesn't even make the top 50 list, more like around 55'ish. The Hubble gets great images because it is in space, and doesn't have to deal with atmosphere and light pollution. It can also catch wavelengths that are largely absorbed by the atmosphere, like infra-red and UV. That makes it extremely useful, however almost all of the ultra-long range research (~13 billion light years) is done with earth based telescopes and fancy corrective s

I'm sure they could add a new detector a few meters from a failed one and compensate for the deviation from perfect geometry in software: they have to have the ability to do that anyway. However, with 5000 detectors they've surely got enough redundancy to tolerate a few dead ones without significant degradation in performance.

I did not say they have a big rate of failure.
By detectors you mean OM, or optical modules. Optical modules are attached to each line.
This problem can't be solved by compensating in the software. if you put your lines to close you will start having problems of the light produced by the muons not reaching other OMs and getting blocked very soon. Spacing is required as there is already few photons to work with.
If an OM is out, it's over. if they have an electrical failure on one of the lines, it's over for that line.
When it was on the sketch board, they took this in consideration, that's why it's big and with so many lines and OMs.
But I repeat if it's out, it's out.